Battery assembly having a heat-dissipating and heat-emitting functions

ABSTRACT

According to one embodiment of the present invention, a battery assembly comprises: a battery module comprising a plurality of unit batteries; an exterior case for housing the battery module in an internal space; and a heat-dissipating film which is inserted between the plurality of unit batteries and fitted tightly against each of the plurality of unit batteries, and is attached to the inside surface of the exterior case; and the heat-dissipating film comprises: first and second heat-dissipating layers which are formed of a thermally conductive material and discharge the heat of the unit batteries; and an adhesive layer which is formed between the first and second heat-dissipating layers and adheres the first and second heat-dissipating layers.

TECHNICAL FIELD

Embodiments of the present invention relate to battery assemblies havingheat-dissipating and heat-emitting functions.

BACKGROUND ART

In existing hybrid vehicles, a hot-wire heater or a ceramic-basedpositive temperature coefficient (PTC) heater is separately mounted tosupply hot air, which is heated by the heater as needed, via a fan,thereby improving battery efficiency.

Existing heaters have high initial inrush current, which results in atleast twice as much current consumption as the heaters need, and areconfigured to supply heated air, thereby causing significant reductionin charge capacity of a battery due to heat generation and high initialcurrent consumption in an initial operation stage. Further, in pureelectric vehicles, the charge amount of the battery directly affectsoperation efficiency, so that the existing heaters are not suitable forsuch electric vehicles.

Thus, one embodiment of the present invention provides a batteryassembly, in which a heater is realized using a planar heating bodycoated with carbon nanotubes (CNTs), such that the heater can be moreuniformly and quickly heated by direct thermal conduction, therebyimproving initial operation efficiency of the battery assembly.

DISCLOSURE Technical Problem

An aspect of the present invention is to provide a battery assemblyhaving heat-dissipating and heat-emitting functions, in which aheat-dissipating and heat-emitting film including a carbon nanotubeheating body (metal-doped carbon nanotubes) is coated on a batterymodule and/or an exterior case, and electrical and heat-conductivecharacteristics of the coated carbon nanotubes are maximized, therebyproviding both the heat-dissipating and heat-emitting function at thesame time.

Another aspect of the present invention is to provide a battery assemblyhaving heat-dissipating and heat-emitting functions, which is capable ofincreasing the battery efficiency of a vehicle, which is reduced due toexternal temperature in initial operation of the vehicle in winter, andcapable of quickly removing heat from the battery during operation ofthe vehicle.

A further aspect of the present invention is to provide a batteryassembly having heat-dissipating and heat-emitting functions, which maycontrol heating temperature of a battery module and/or an exterior caseusing a temperature sensor and a controller to maintain the batterytemperature under an optimum condition (0-30° C.), thereby preventingfire due to battery overheating.

Aspects of the present invention are not limited to these aspects andother aspects of the present invention will become apparent to thoseskilled in the art from the following description.

Technical Solution

In accordance with one aspect of the present invention, aheat-dissipating film includes: first and second heat-dissipating layersformed of a thermally conductive material and discharging heat of unitbatteries; and an adhesive layer formed between the first and secondheat-dissipating layers to attach the first and second heat-dissipatinglayers to each other.

The heat-dissipating film may further include a heat-emitting filmformed between the first heat-dissipating layer and the adhesive layer.

The heat-emitting film may include a base layer on which an electrodelayer and a carbon nanotube (CNT) heating body are printed; and aninsulating layer formed between the electrode layer of the base layerand the first heat-dissipating layer to attach the base layer to thefirst heat-dissipating layer while insulating the electrode layer andthe first heat-dissipating layer from each other.

The carbon nanotube heating body may be formed by doping, on surfaces ofcarbon nanotubes, at least one metal selected from among Ag, Cu, Ni, Au,Pt, and Pd.

The insulating layer may be a double-sided adhesive film formed of anyone adhesive selected from among acrylic adhesives, hot-melt adhesives,silicone adhesives, and rubber adhesives.

The electrode layer of the base layer may be electrically connected toboth an anode and a cathode of each of the unit batteries to provide aheat-emitting function to the carbon nanotube heating body.

The base layer may be formed of at least one material selected fromamong biaxially oriented polyester (BOPET), polyethylene terephthalate(PET), oriented polystyrene (OPS), oriented polypropylene (OPP),polyethylene naphthalate (PEN), polyether sulfone (PES), polyphenylenesulfide (PPS), polyimide (PI), and polyether imide (PEI).

The adhesive layer may be a double-sided tape formed of any one selectedfrom among acrylic tapes, hot-melt tapes, silicone tapes, and rubbertapes.

In accordance with another aspect of the present invention, a batteryassembly includes: a battery module including a plurality of unitbatteries; an exterior case for housing the battery module in aninternal space; and a heat-dissipating film inserted between theplurality of unit batteries to tightly contact each of the unitbatteries and to be attached to an inner surface of the exterior case.Here, the heat-dissipating film includes: first and secondheat-dissipating layers formed of a thermally conductive material anddischarging heat of the unit batteries; and an adhesive layer formedbetween the first and second heat-dissipating layers to attach the firstand second heat-dissipating layers to each other.

The battery assembly may further include a heat-emitting film formedbetween the first heat-dissipating layer and the adhesive layer.

The heat-emitting film may include a base layer on which an electrodelayer and a carbon nanotube (CNT) heating body are printed; and aninsulating layer formed between the electrode layer of the base layerand the first heat-dissipating layer to attach the base layer to thefirst heat-dissipating layer while insulating the electrode layer andthe first heat-dissipating layer from each other.

The battery assembly may further include: a temperature sensor providedto at least one of the unit batteries; and a controller controllingpower supply to the electrode layer of the base layer based ontemperature detection results from the temperature sensor.

In accordance with a further aspect of the present invention, anexterior case includes a heat-dissipating film attached to an innersurface thereof and discharges heat generated from unit batteries,wherein the heat-dissipating film includes: first and secondheat-dissipating layers formed of a thermally conductive material anddischarging heat from the unit batteries; and an adhesive layer formedbetween the first and second heat-dissipating layers to attach the firstand second heat-dissipating layers to each other.

The exterior case may further include a heat-emitting film formedbetween the first heat-dissipating layer and the adhesive layer.

The heat-emitting film may include a base layer on which an electrodelayer and a carbon nanotube (CNT) heating body are printed; and aninsulating layer formed between the electrode layer of the base layerand the first heat-dissipating layer to attach the base layer to thefirst heat-dissipating layer while insulating the electrode layer andthe first heat-dissipating layer from each other.

The exterior case may further include: a temperature sensor provided toat least one inner surface of the exterior case; and a controllercontrolling power supply to the electrode layer of the base layer basedon temperature detection results from the temperature sensor.

Details of other embodiments will be described in the detaileddescription with reference to the accompanying drawings.

The above and other aspects, features, and advantages of the inventionwill become apparent from the detailed description of the followingembodiments in conjunction with the accompanying drawings. It should beunderstood that the present invention is not limited to the followingembodiments and may be embodied in different ways, and that theembodiments are provided for complete disclosure and thoroughunderstanding of the invention by those skilled in the art. The scope ofthe invention is defined only by the claims. Like components will bedenoted by like reference numerals throughout the specification.

Advantageous Effects

According to one embodiment of the present invention, there is provideda battery assembly having heat-dissipating and heat-emitting functions,in which a heat-dissipating and heat-emitting film having a carbonnanotube heating body is coated on a battery module and/or an exteriorcase, and electrical and heat-conductive characteristics of the coatedcarbon nanotubes are maximized, thereby providing both theheat-dissipating and heat-emitting function at the same time.

According to one embodiment of the present invention, there is provideda battery assembly having heat-dissipating and heat-emitting functions,which is capable of increasing battery efficiency of a vehicle even whenthe vehicle initially operates in winter, and capable of rapidlyremoving heat from the battery during operation of the vehicle.

According to one embodiment of the present invention, there is provideda battery assembly having heat-dissipating and heat-emitting functions,which controls the heating temperature of a battery module and/or anexterior case using a temperature sensor and a controller, such thatbattery temperature can be maintained under an optimum condition (0-30°C.), thereby preventing fire due to battery overheating.

DESCRIPTION OF DRAWINGS

FIG. 1 is a graphical diagram showing test results on dischargeefficiency with respect to ambient temperature in a battery modulemounted in an electric vehicle.

FIG. 2 is an exploded perspective view of a battery assembly accordingto one embodiment of the present invention.

FIG. 3 is an assembled perspective view of the battery assemblyaccording to the embodiment of the present invention.

FIG. 4 is a view of a stack structure of a heat-dissipating andheat-emitting film formed on a battery module and an exterior case shownin FIG. 2.

FIG. 5 is a view of an exemplary process for individually controllingthe heating temperature of the exterior case using a temperature sensorand a controller.

FIG. 6 is a view of an exemplary process for controlling the heatingtemperature of both the battery module and the exterior case using thetemperature sensor and the controller.

BEST MODE

FIG. 1 is a graphical diagram showing test results on dischargeefficiency with respect to ambient temperature in a battery modulemounted in an electric vehicle.

Referring to FIG. 1, it can be seen that battery efficiency is graduallydegraded at 20° C. or less below zero and at 40° C. above zero duringdischarge.

Further, in Table 1, it can be seen that, for a 1200 Wh product, thedischarge efficiency is 88% at 10° C. below zero and 66% at 20° C. belowzero. Thus, a preferred temperature ranges from 0° C. to 30° C. tomaintain a battery in an optimum operating condition.

Therefore, the present invention provides a battery module, an exteriorcase, and a battery assembly having these components, which are capableof increasing battery efficiency of a vehicle, which can be reduced dueto external temperature when the vehicle initially operates in winter,and capable of quickly removing heat from the battery generated duringoperation of the vehicle.

To this end, according to one embodiment of the present invention,carbon nanotubes (CNT) are coated on a battery module and/or an exteriorcase in a constant pattern, and electrical and heat-conductivecharacteristics of the coated carbon nanotubes are maximized, therebyproviding both the heat-dissipating and heat-emitting function at thesame time.

Although carbon nanotubes are used as a material having heat-dissipatingand heat-emitting functions in some embodiments of the invention, it isdifficult to provide such heat-dissipating and heat-emitting functionsusing pure carbon nanotubes alone.

Thus, according to some embodiments, the carbon nanotubes may be dopedwith metal (metal doped CNT) to maximize heat-dissipating andheat-emitting characteristics. Methods for coating the metal doped CNTon the battery module or the exterior case include pad printing, spraycoating, printing using a transfer film, and the like. According to oneembodiment, a uniform metal doped CNT layer may be formed on a 3-Dcontour using such coating methods.

Such a conductive layer may provide a heat-dissipating function todissipate heat from the battery module in a normal state, and mayreceive electric energy to emit heat, as needed.

According to one embodiment of the invention, a CNT coating filmproviding both a heat-dissipating function and a heat-emitting functionmay be disposed between flat batteries and connected to the batterymodule or the exterior case, thereby maximizing battery efficiency.

According to one embodiment of the invention, since excessiveheat-emission can cause explosion of the battery, a controller may beused to maintain battery efficiency, thereby preventing fire due toheat-emission of the battery and thereby securing safety.

According to the embodiment of the invention, in an initial operatingstage of a heater, inrush current is not generated, such that excessivecurrent is not generated and the battery is uniformly and rapidlyheated, thereby improving heat-emitting efficiency.

Embodiments of the present invention may provide heat-dissipating andheat-emitting features by applying a coating to a high-strength plasticexterior case, which is manufactured by prepregging polyphenylenesulfide (PPS), epoxy, polypropylene (PP), polyethylene (PE), polyamide(PA) or the like into glass fibers, pitch based carbon fibers, polyacrylnitrile (PAN)-based carbon fibers, pitch based carbon chopped fibers, orpitch based milled fibers, as well as stainless steel (SUS) or Alexterior cases, which are generally used to form exterior casings ofbatteries.

Embodiments of the present invention will now be described in detailwith reference to the accompanying drawings.

FIG. 2 is an exploded perspective view of a battery assembly accordingto one embodiment of the present invention, FIG. 3 is an assembledperspective view of the battery assembly according to the embodiment ofthe present invention, and FIG. 4 is a view of a stack structure of aheat-dissipating and heat-emitting film formed on a battery module andan exterior case shown in FIG. 2.

Referring first to FIGS. 2 and 3, a battery assembly 200 according toone embodiment of the invention may include a battery module, anexterior case 220, and a heat-dissipating and heat-emitting film 230.

The battery module includes a plurality of unit batteries 210. Each ofthe unit batteries 210 includes an anode 212 serving as a positiveelectrode, and a cathode 214 serving as a negative electrode. Theheat-dissipating and heat-emitting film 230 is interposed in a closelycompact manner between the unit batteries 210. Details of theheat-dissipating and heat-emitting film 230 will be described below withreference to FIG. 4.

The exterior case 220 receives the plurality of unit batteries 210therein. That is, the exterior case 220 serves as a cover for theplurality of unit batteries 210. The heat-dissipating and heat-emittingfilm 230 may also be attached to an inner surface of the exterior case220.

Although the heat-dissipating and heat-emitting film 230 is described asbeing formed both between the plurality of unit batteries 210 and on theinner surface of the exterior case 220 in this embodiment, the presentinvention is not limited thereto. Thus, various heat-dissipating andheat-emitting films 230 may be formed only between the unit batteries210, or otherwise the heat-dissipating and heat-emitting film 230 may beformed only on the inner surface of the exterior case 220.

The heat-dissipating and heat-emitting film 230 may include aheat-dissipating film which dissipates heat from the plurality of unitbatteries 210, and a heat-emitting film which emit heat upon receivingpower.

The heat-dissipating and heat-emitting film 230 will be described inmore detail with reference to FIG. 4. For reference, FIG. 4 shows astack structure of the heat-dissipating and heat-emitting film 230 ofFIG. 1.

As shown in FIG. 4, the heat-dissipating and heat-emitting film 230 mayinclude a first heat-dissipating layer 410, an insulating layer 420, anelectrode layer 430, a carbon nanotube heating body 440, a base layer450, an adhesive layer 460, and a second heat-dissipating layer 470.

The first heat-dissipating layer 410 is formed not only on each of thesurfaces of the unit batteries 210, but also on the inner surface of theexterior case 220. The first heat-dissipating layer 410 may be formed ofa thermally conductive material such as Al, Cu or the like, to dissipateheat from the unit batteries.

The insulating layer 420 is formed on the first heat-dissipating layer410. The insulating layer 420 is interposed between the firstheat-dissipating layer 410 and the electrode layer 430 to insulate thefirst heat-dissipating layer 410 and the electrode layer 430 from eachother while allowing adhesion therebetween.

To this end, the insulating layer 420 may be realized by a double-sidedadhesive film composed of adhesives, such as acrylic adhesives, hot-meltadhesives, silicone adhesives, rubber adhesives, and the like.

The electrode layer 430 is formed on the insulating layer 420. Asdescribed above, the electrode layer 430 is attached to the insulatinglayer 420. The electrode layer 430 may be formed of an electricallyconductive material, such as Ag, Cu, Au, Al or the like.

Such an electrode layer 430 may be electrically connected to the anode(positive electrode) and the cathode (negative electrode) of each of theunit batteries 210 to provide a heat-emitting function to the carbonnanotube heating body 440.

The carbon nanotube (CNT) heating body 440 is formed on the electrodelayer 430. The carbon nanotube heating body 440 may be formed by dopingmetal on the carbon nanotube surface.

Although carbon nanotubes are known to have excellent electric andheat-conductive characteristics, if the carbon nanotubes are used ascoating pastes, there can be a problem of deterioration in electricalconductivity due to dispensability and increased contact resistance ofthe carbon nanotubes in a 3D contoured product.

Accordingly, in some embodiment of the present embodiment, metal dopedcarbon nanotubes are used instead of pure carbon nanotubes so as toprovide effects of improving electrical conductivity and thermalconductivity.

When the carbon nanotubes are coated with metal, infrared (IR)wavelengths are reflected by the metal and heat-dissipatingcharacteristics are improved, whereby the carbon nanotube heating bodyis also suitably used as a heat-dissipating coating material.

Here, the metal may include at least one selected from among Ag, Cu, Ni,Au, Pt, and Pd.

The base layer 450 is formed on the carbon nanotube heating body 440.The base layer 450 may be formed of at least one material selected fromamong biaxially oriented polyester (BOPET), polyethylene terephthalate(PET), oriented polystyrene (OPS), oriented polypropylene (OPP),polyethylene naphthalate (PEN), polyether sulfone (PES), polyphenylenesulfide (PPS), polyimide (PI), and polyether imide (PEI).

The adhesive layer 460 is formed on the base layer 450. The adhesivelayer 460 serves to attach the base layer 450 and the firstheat-dissipating layer 470 to each other. To this end, the adhesivelayer 460 may be realized by a double-sided tape composed of at leastone of acrylic tapes, hot-melt tapes, silicone tapes, and rubber tapes.

The second heat-dissipating layer 470 is formed on the adhesive layer460. The second heat-dissipating layer 470 serves to dissipate heat fromthe unit batteries. To this end, the second heat-dissipating layer 470may be formed of a thermally conductive material such as Al, Cu or thelike.

For reference, the first and second heat-dissipating layers 410, 470 andthe adhesive layer 460 correspond to the heat-dissipating film, and theinsulating layer 420, the electrode layer 430, the carbon nanotubeheating body 440, and the base layer 450 correspond to the heat-emittingfilm.

Now, a method of manufacturing the heat-dissipating and heat-emittingfilm 230 will be described.

First, the electrode layer 430 and the carbon nanotube heating body 440are printed on one side of the base layer 450.

Next, the first heat-dissipating layer 410 is placed below the electrodelayer 430, the insulating layer 420 is disposed between the firstheat-dissipating layer and the electrode layer, and the base layer 450on which the electrode layer and the carbon nanotube heating body 440are printed is attached to the first heat-dissipating layer 410.

Then, the second heat-dissipating layer 470 is placed on the other sideof the base layer 450, the adhesive layer 460 is disposed between thebase layer and the second heat-dissipating layer, and the base layer 450attached to the first heat-dissipating layer 410 is attached to thesecond heat-dissipating layer 470.

The heat-dissipating and heat-emitting film 230 may be manufactured bythis process. The heat-dissipating and heat-emitting film 230 may becoated on the unit batteries 210 and the exterior case 220 by padprinting, spray coating, printing using a transfer film, or the like.

The battery assembly 200 according to one embodiment of the inventionmay further include a temperature sensor 240 and a controller (640 inFIG. 6).

The temperature sensor 240 may be provided to at least one of the unitbatteries 210 to detect the temperature of the unit battery 210. In thisembodiment, the temperature sensor 240 may be a negative temperaturecoefficient (NTC) sensor.

The controller controls power supply to the electrode layer 430 based ontemperature detection results of the temperature sensor 240. Thus, thecontroller may allow the unit battery 210 to maintain an optimaltemperature condition ranging from 0 to 30 degrees. In the presentembodiment, the controller may be an electronic control unit (ECU)controller of a vehicle (particularly an electric vehicle).

Now, the process of controlling heat emitted from the exterior case orthe battery module using the temperature sensor and the controller willbe described with reference to FIGS. 5 and 6.

FIG. 5 is a view of an exemplary process for individually controllingthe heating temperature of the exterior case using a temperature sensorand a controller, and FIG. 6 is a view of an exemplary process forcontrolling the heating temperature of both the battery module and theexterior case using the temperature sensor and the controller.

As shown in FIG. 5, a heat-dissipating and heat-emitting film is coatedon the inner surface of an exterior case 510, and an NTC sensor 520(temperature sensor) is attached to the heat-dissipating andheat-emitting film. The NTC sensor 520 detects the temperature of heatemitted from the exterior case 510 and sends the detection result(temperature) to an ECU controller 530.

The ECU controller 530 regulates power supply to the heat-dissipatingand heat-emitting film of a battery 540 based on the detectedtemperature, thereby maintaining a suitable temperature of the exteriorcase 510.

Next, as shown in FIG. 6, a heat-dissipating and heat-emitting film iscoated on a battery module 610, and an NTC sensor 620 (temperaturesensor) is attached to the heat-dissipating and heat-emitting film. TheNTC sensor 620 detects the temperature of heat emitted from the batterymodule 610 and sends the detection result (temperature) to an ECUcontroller 640.

The ECU controller 640 regulates power supply to a battery 650 based onthe detected temperature, thereby controlling power supply to theheat-dissipating and heat-emitting film inserted into or coated on thebattery module 610 and the exterior case 630. As a result, the ECUcontroller 640 may maintain the temperature of the battery module 610and the exterior case 630 to be under optimal conditions (0-30° C.).

According to the embodiment, a heat-dissipating and heat-emitting filmhaving a carbon nanotube heating body (metal doped carbon nanotubes) iscoated on a battery module and/or an exterior case, and electrical andheat-conductive characteristics of the coated carbon nanotubes aremaximized, thereby providing both the heat-dissipating and heat-emittingfunctions at the same time.

According to the embodiment, it is possible to increase batteryefficiency of a vehicle, which is reduced due to external temperaturewhen the vehicle initially operates in winter, and to achieve rapidremoval of heat from the battery during operation of the vehicle.

According to the embodiment, the heating temperature of a battery moduleand/or an exterior case is controlled using a temperature sensor and acontroller, such that the battery temperature can be maintained under anoptimum condition (0-30° C.), thereby preventing fire due to batteryoverheating.

Although some embodiments have been described herein, it will beunderstood by those skilled in the art that these embodiments areprovided for illustration only, and various modifications, changes,alterations and equivalent embodiments can be made without departingfrom the scope of the present invention. Therefore, the scope and spritof the present invention should be defined only by the accompanyingclaims and equivalents thereof.

EXAMPLES Heat-Dissipating Effects of Heat-Dissipating Film Example 1

A carbon nanotube heating body and an Ag electrode layer were printed ona base layer composed of biaxially oriented polyethylene terephthalate(BOPET). The carbon nanotube heating body was formed by doping Ag on thesurfaces of carbon nanotubes. Next, with a first heat-dissipating layerplaced below the electrode layer, an insulating layer composed of anacrylic adhesive was interposed therebetween, and the base layer onwhich the electrode layer and the carbon nanotube heating body wereprinted was attached to the first heat-dissipating layer.

Next, with a second heat-dissipating layer placed on the other side ofthe base layer, a silicone adhesive layer was interposed therebetween,and the base layer adhered to the first heat-dissipating layer wasattached to the second heat-dissipating layer.

Example 2

A carbon nanotube heating body was printed on a base layer composed ofbiaxially oriented polyethylene terephthalate (BOPET). The printedcarbon nanotube heating body was coated with a Cu electrode layer. Thecarbon nanotube heating body was formed by doping Cu on the surfaces ofcarbon nanotubes. Next, with a first heat-dissipating layer placed belowthe electrode layer, an insulating layer composed of an acrylic adhesivewas interposed therebetween, and the base layer on which the electrodelayer and the carbon nanotube heating body were printed was attached tothe first heat-dissipating layer.

Next, with a second heat-dissipating layer placed on the other side ofthe base layer, a silicone adhesive layer was interposed therebetween,and the base layer adhering to the first heat-dissipating layer wasattached to the second heat-dissipating layer.

Comparative Example 1

A sample was manufactured in the same manner as in Example 1 except fora carbon nanotube heating body was not included therein.

Comparative Example 2

A sample was manufactured in the same manner as in Example 1 except thatpure carbon nanotubes were used instead of the Ag-doped carbonnanotubes.

Heat-dissipating effects by the heat-dissipating films of Examples 1 and2 and Comparative Examples 1 and 2 were measured in such a manner thatsamples were attached to a 2 mm thick A5052 Al plate placed on a flat DCheater using a highly thermally-conductive adhesive resin (3.6 W/mK) andheated to a certain temperature, and subsequently, after the heater wasturned off, the surface temperature was measured using a K-typethermocouple at certain time intervals. As a result, a portion otherthan heat-dissipating film-attached portions had constant temperature,and the heat-dissipating film-attached portions had differenttemperature-reduction rates according to heat-dissipating effects of theheat-dissipating films.

Temperature measurement results of the heat-dissipating films ofExamples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1below.

TABLE 1 Comparative Comparative Example 1 Example 2 Example 1 Example 2Time (° C.) (° C.) (° C.) (° C.) 1 0 80.0 80.0 80.0 80.0 2 After 3 min77.8 78.0 79.0 79.1 3 After 6 min 75.7 76.0 77.3 78.3 4 After 9 min 73.773.8 75.4 76.4 5 After 12 min 71.4 71.4 74.8 75.1 6 After 15 min 69.269.2 73.2 74.8

As shown in Table 1, it could be seen that Examples 1 and 2 showed muchgreater temperature-reduction than Comparative Examples 1 and 2 that didnot contain a carbon nanotube heating body. That is, it could be seenthat considerable temperature-reduction of a heat-emitting product wasobtained by the provision of the heat-emitting film having the carbonnanotube heating body. As a result, the heat-dissipating film accordingto the present invention clearly exhibits vastly superior thermalconductivity.

Although some embodiments have been described herein with reference tothe accompanying drawings, it will be understood by those skilled in theart that these embodiments are provided for illustration only, andvarious modifications, changes, alterations and equivalent embodimentscan be made without departing from the scope of the present invention.Therefore, the scope and sprit of the present invention should bedefined only by the accompanying claims and equivalents thereof.

The invention claimed is:
 1. A heat-dissipating film comprising: firstand second heat-dissipating layers formed of a thermally conductivematerial that discharges heat of unit batteries; an adhesive layerformed between the first and second heat-dissipating layers to attachthe first and second heat-dissipating layers to each other; aheat-emitting film formed between the first heat-dissipating layer andthe adhesive layer, wherein the heat-emitting film comprises: a baselayer on which an electrode layer and a carbon nanotube heating body areprinted; and an insulating layer formed between the electrode layer ofthe base layer and the first heat-dissipating layer to attach the baselayer to the first heat-dissipating layer while insulating the electrodelayer and the first heat-dissipating layer from each other.
 2. Theheat-dissipating film according to claim 1, wherein the carbon nanotubeheating body is formed by doping, on surfaces of carbon nanotubes, atleast one metal selected from among Ag, Cu, Ni, Au, Pt, and Pd.
 3. Theheat-dissipating film according to claim 1, wherein the insulating layeris a double-sided adhesive film formed of any one adhesive selected fromamong acrylic adhesives, hot-melt adhesives, silicone adhesives, andrubber adhesives.
 4. The heat-dissipating film according to claim 1,wherein the electrode layer of the base layer is electrically connectedto both an anode and a cathode of each of the unit batteries to providea heat-emitting function to the carbon nanotube heating body.
 5. Theheat-dissipating film according to claim 1, wherein the base layer isformed of at least one material selected from among biaxially orientedpolyester, polyethylene terephthalate, oriented polystyrene, orientedpolypropylene, polyethylene naphthalate, polyether sulfone,polyphenylene sulfide, polyimide, and polyether imide.
 6. Theheat-dissipating film according to claim 1, wherein the adhesive layeris a double-sided tape formed of any one selected from among acrylictapes, hot-melt tapes, silicone tapes, and rubber tapes.